President Obama and First Lady Michelle Obama are marking the tenth anniversary of the worst attacks on our country by joining ceremonies at each of the three sites where the planes crashed on September 11, 2001.

They played the bagpipes again and recited the names of the dead like poetry. Bells tolled, and requiems by President Obama and other dignitaries filled the amphitheater of ground zero on Sunday as America looked back upon a contagion of terrorism and war and renewed its vows of remembrance.

On 11 September it will be exactly a decade since al-Qaeda flew passenger jets into the New York skyscrapers, the Twin Towers. A third plane crashed into America’s military headquarters the Pentagon and a fourth crashed in a field when passengers tried to overpower their hijackers.